Angular surface solitons in sectorial hexagonal arrays

Abstract

We report on the experimental observation of corner surface solitons localized at the edges joining planar interfaces of hexagonal waveguide array with uniform nonlinear medium. The face angle between these interfaces has a strong impact on the threshold of soliton excitation as well as on the light energy drift and diffraction spreading.OCIS codes: 190.0190, 190.6135 Over the last several years there has been growing interest to linear and nonlinear optical surface waves. After the prediction of discrete surface solitons at the interface of uniform material and waveguide array with focusing nonlinearity [1] and at the interface between dissimilar arrays [2] and their subsequent observations [3][4][5], a burst of new findings revolutionized the perception of nonlinear surface waves. For example, solitons were also found at the edge of defocusing lattices [6][7][8]. Special attention was given to two-dimensional (2D) geometries [2,9-11]. 2D surface solitons were observed in optically induced lattices [12] and in laser-written waveguide arrays [13,14]. However, up to now the impact of the geometry of the interface on the properties of 2D surface solitons was not addressed properly. To bridge this gap, we report in this Letter the salient features of 2D solitons localized at the edges joining planar interfaces of a hexagonal waveguide array with a uniform nonlinear medium and show that the face angle is the key parameter defining the power threshold for soliton excitation and the direction of the light energy drift and diffraction spreading.

Self-trapping of optical vortices at the surface of an induced semi-infinite photonic lattice

“…Discrete surface solitons were first proposed and experimentally demonstrated at the edge of one-dimensional (1(d) photonic lattices [3][4][5][6][7], and subsequently they were also suggested and observed in 2D optical settings [8][9][10]. In fact, the phenomena of nonlinear surface states were enriched by prediction and demonstration of a variety of surface or interface solitons in the 2D domain, including multipole mode surface solitons [11], angular surface solitons [12], lattice interface solitons [13], and surface soliton arrays [14], to name just a few. Despite of these efforts on surface solitons, to our knowledge, no experimental work has investigated self-trapping of optical vortices at the surfaces of optical periodic structures.…”

Observation of two-dimensional coherent surface vector lattice solitons

“…The properties of solitons at interfaces between uniform and periodic media have much in common with those shown by surface solitons at interfaces between natural materials, as predicted in [13]. Scalar lattice surface solitons have been observed at the edges of one- [14] and two-dimensional [15][16][17] periodic lattices. However, lattice interfaces also support vector solitons.…”

Nonlinear light localization around the core of a holey fiber

“…By propagating a vortex mode in waveguides around the solid core of a PCF we can study vortex modes interacting with a surface, where the periodic structure meets a homogenous dielectric. Such states have been studied and observed in similar structures for single site excitation with Gaussian modes [19,20]. This paper is organized as follows: Section II introduces the discrete model for an infiltrated PCF structure with an hexagonal geometry and a central defect making a solid core, in section III we introduce the continuous model of the same structure, focussing on the dynamical evolution of vortex excitations and finally, section IV concludes the paper.…”